Reed relay termingal construction



Dec. 19, 1967 M. w. BRUCE 3,359,395

REED RELAY TERMINAL CONSTRUCTION Filed July 25, 1966 u 62 r f 7 Zita-m United States Patent 3,359 395 REED RELAY TERMIblAL CONSTRUCTION Morris W. Bruce, Princeton, Ind., assignor to Essex Wire Corporation, Fort Wayne, Ind., a corporation of Michigan Filed July 25, 1966, Ser. No. 567,598 8 Claims. (Cl. 200-166) ABSTRACT OF THE DISCLOSURE A reed relay mounting assembly in which the reed cartridge is inserted into the barrel portion of a coilcarrying bobbin, the terminals of the reed switch cartridge being interconnected with terminals mounted on the bobbin assembly. The cartridge terminals are notched to interlock with slots in the bobbin terminals when the reed switch cartridge is rotated. The bobbin is provided with a hood at each end which surrounds and protects the cartridge terminals. Slots in the bobbin end flanges receive coil wires leading from the barrel portion of the bobbin to coil terminals which are mounted outside the cartridge terminal hood.

Background of the invention This invention relates to an improved mounting assembly for incapsulated reed switches.

Because of their ability to resist contact contamination, incapsulated reed switch relays have found wide acceptance in a variety of applications. These switches normally comprise a pair of magnetizable leaf springs mounted within a sealed, tubular capsule. The leaf spring arms overlap such that, when the capsule is subjected to an axial magnetic field, the leaf spring arms are pulled into contact to close a circuit path. Commonly, the reed switch capsules are mounted within the barrel portion of an insulated bobbin upon which the magnetizing coil is wound. At the ends of the incapsulated switch, the reed arms are soldered or welded to terminals which provide a convenient mode of connecting the switch to a printed circuit board or the like. One such prior art mounting arrangement for connecting reed switches to a circuit board is shown in U.S. Patent 3,238,327 which issued to J. V. Koppensteiner on Mar. 1, 1966.

Summary of the invention It is a general object of the present invention to provide secure electrical and mechanical connections between the incapsulated reed switch terminals and the associated circuit terminals within the reed relay assembly.

It is a further object of the present invention to provide an easily assembled reed relay mounting arrangement suitable for use in conjunction with printed or etched circuit boards.

It is a still further object of the invention to facilitate removal and replacement of a defective reed switch capsule.

In a principal aspect, the present invention takes the form of an improved reed switch assembly which includes an insulated bobbin including a hollow barrel portion for receiving at least one elongated, incapsulated reed switch. Out-wardly projecting circuit terminals are fastened to the bobbin. In accordance with a first feature of the invention, each circuit terminal includes an elongated slot positioned to receive one terminal of a reed switch. Each reed switch capsule is provided with a terminal which extends axially outward from the end of the capsule. According to -a second feature of the invention, the end of each switch terminal includes a constricted region flanked by a pair of enlarged regions.

The outermost one of these enlarged regions is flattened such that it has a greater width than thickness. In accordance with the invention, the aforementioned slot possesses a long and a short dimension, the short dimension being greater than the thickness but shorter than the width of the outermost enlarged region such that, when the constricted region of the switch terminal is positioned within the slot in the circuit terminal, the switch may be bodily rotated to lock the switch terminal and the circuit terminal together. In consequence, the incapsulated reed switch is held firmly against axial motion and secure electrical and mechanical connections are made between the reed arms of the switch and the circuit terminals.

These and other objects, features and advantages of the present invention may be more clearly understood through a consideration of the following detailed description. In the course of this description, reference will frequently be made to the attached drawings:

Brief description of the drawings FIG. 1 is a perspective view of a reed switch assembly constructed in accordance with the principles of the invention;

FIG. 2 is an end view of the reed switch assembly shown in FIG. 1;

FIG. 3 is a partial side view showing one end of the reed switch assembly illustrated in FIGS. 1 and 2; and

FIG. 4 is an enlarged perspective view showing the manner in which the switch terminals are securely locked to the circuit terminals as contemplated by the invention.

Description of the preferred embodiment The reed relay assembly shown in FIG. 1 comprises a bobbin having a central, hollow barrel portion indicated generally at 11 terminated at its ends by the coil retaining flanges shown generally at 13 and 15. The magnetizing coil (or coils) employed to control the operation of the switching relays are not shown. The nearer end of the assembly shown in FIG. 1 includes a base section 17 and a hood portion indicated generally at 19. Similarly, the other end of the bobbin 11 comprises a base section 21 and a hood section 22. Four circuit terminals 23 through 26 are securely fastened to the base section 17. The hood 19 helps prevent inadvertent contact with these contacts. The outside circuit terminals 23 and 26 are employed to provide circuit connections for the magnetizing coil (or coils) wound on the barrel portion 11 of the bobbin. Notches 29 cut in the flange portions 13 and 15 provide passages for the coil wire between the coil and these outer circuit terminals for the windings.

As illustrated most clearly in the enlarged perspective view of circuit terminal 25 in FIG. 4, each of the terminals 23 through 26 includes a pair of inwardly extending lugs 31 and 32. The lugs 31 and 32 extend through rectangular openings in the base section 17 and may then be bent toward one another and crimped in place to secure the associated terminal to the base section 17. The outer face of both base sections 17 and 21 are provided with four cross-shaped recesses (seen most clearly in FIG. 1) which receive the circuit terminals, further securing these terminals against both vertical and horizontal movement.

Further details of the circuit terminal 25 are shown in FIG. 4 of the drawings. Terminal 25 includes a downwardly extending member 37 (which may be received in a pre-drilled circuit board slot) and a pair of substantially right-angle bends indicated at 38 and 39 in FIG. 4-. The enlarged member 40 which extends upwardly from the right-angle bend 39 includes a rectangular .slot 42 which possesses a greater height than width. The slot 42 receives the end portion of the switch terminal indicated generally at 43'. The switch terminal 43 extends axially outward from the end of the envelope 44 of one of the reed switches.

The switch terminal end portion 43 includes a constricted region indicated generally at 50 defined by a pair of lateral notches cut into the sides of the end portion 43. The constricted region 50 is accordingly flanged by a pair of enlarged regions 51 and 52, each of which has a greater width than thickness. To connect the switch and circuit terminals, the end portion 43 is inserted into the slot 42 and the switch capsule is rotated bodily by approximately 90 to lock the reed switch capsule against axial movement. The turning radius of the constricted region 50 is shorter than the width of slot 42 to permit rotation. 7

After the reed switches have been rotated to their locked position, the terminals may be soldered to further secure the connection. As can be readily appreciated from FIGS. 1 and 4 of the reed switch drawings, the novel terminal locking arrangement contemplated by the present invention secures the reed switches against axial movement within the bobbin 11, provides a secure mechanical and electrical connection between the reed switch terminals and the circuit terminals, and greatly simplifies the construction of the switch by eliminating the necessity for wired connections.

To remove a defective reed switch cartridge, it is merely necessary to unsolder the terminals, rotate the reed switch to the unlocked position, bend one of the associated circuit terminals outward, and remove the switch cartridge from the barrel portion 11. A properly functioning reed switch may then be inserted and locked into position using the reverse procedure.

It is to be understood that the embodiment of the invention which has been described is merely illustrative of one application of the principles of the invention. Numerous modifications may be made by those skilled in the art without departing from the true spirit and scope of the invention.

What is claimed is:

1. In combination, an elongated, reed switch cartridge including a switch terminal extending outwardly from each end thereof, the end of each of said switch terminals including a constricted region flanked by a pair of enlarged regions, the outermost one of said enlarged regions having a greater width than thickness, an insulated bobbin including a hollow barrel portion, said cartridge being positioned in said barrel portion, a circuit terminal fastened to said bobbin at each end of said barrel portion, each of said circuit terminals including an elongated slot receiving one of said switch terminals, said slot having long and short dimensions, said short dimension being greater than the thickness but shorter than the width of the outermost one of said enlarged regions of said switch terminal such that, when said constricted regions are positioned within said slots, said switch may be rotated to lock said switch terminals to said circuit terminal.

2. An arrangement as set forth in claim 1 wherein the turning radius of said constricted region is smaller than the short dimension of said slot,

' 5 rectangular cross-section is smaller than the narrowest dimension of said slot.

4. A combination as set forth in claim 3 including a hood affixed to the ends of said bobbin for preventing inadvertent contact with said circuit terminals.

5. A combination as set forth in claim 4 including a pair of inwardly extending lugs affixed to each of said circuit terminals and adapted to extend through and be crimped against a portion of said bobbin.

6. An improved reed switch assembly comprising, in combination,

an elongated, insulated reed switch bobbin having a hollow barrel portion adapted to slidably receive at least one reed switch cartridge, said bobbin having end portions disposed at each end of said barrel por tion, each of said end portions having terminal retaining recesses;

at least one elongated reed switch cartridge slidably mounted in said barrel and having a switch terminal extending outwardly from each end of said barrel, each of said switch terminals comprising a flat planar plate section having a first and a second notch defined therein, said first and second notches being opposite one another; and

a circuit terminal associated with each of said switch terminals and having an elongated slot to slidably receive one of said switch terminals, said slot adapted to lock said switch terminal in a substantially immovable position when said reed switch is rotated to bring said first and second notches in an interlocking relationship with said slot, said circuit terminals being retained in a substantially immovable position in said terminal retaining recesses.

7. The assembly of claim 6 including lug receiving slots defined in said end portions, and including circuit terminal lugs attached to said circuit terminals and engaging said lug slots, said lugs being ben to hold said circuit terminals in a substantially immovable position on said end portion of said bobbin.

8. The assembly of claim 6 including coil terminals 45 attached to said end portions and including coil wire slots defined in said end portions to receive coil wires from a coil wrapped about said barrel portion, and coil Wires being attached to said coil terminals.

References Cited UNITED STATES PATENTS 1,631,288 6/1927 Potter 339272 2,580,105 12/1951 Krumreich 200166 2,713,672 7/1955 Allen 339272 3,215,794 11/1965 Zielinski 335152 3,238,327 3/1966 Koppensteiner 335-152 FOREIGN PATENTS 723,759 12-1965 Canada.

ROBERT K. SCHAEFER, Primary Examiner.

O. JONES, Assistant Examiner, 

1. IN COMBINATION, AN ELONGATED, REED SWITCH CARTRIDGE INCLUDING A SWITCH TERMINAL EXTENDING OUTWARDLY FROM EACH END THEREOF, THE END OF EACH OF SAID SWITCH TERMINALS, INCLUDING A CONSTRICTED REGION FLANKED BY A PAIR OF ENLARGED REGIONS, THE OUTERMOST ONE OF SAID ENLARGED REGIONS HAVING A GREATER WIDTH THAN THICKNESS, AN INSULATED BOBBIN INCLUDING A HOLLOW BARREL PORTION, SAID CARTRIDGE BEING POSITIONED IN SAID BARREL PORTION, A CIRCUIT TERMINAL FASTENED TO SAID BOBBIN AT EACH END OF SAID BARREL PORTION, EACH OF SAID CIRCUIT TERMINALS INCLUDING AN ELONGATED SLOT RECEIVING ONE OF SAID SWITCH TERMINALS, SAID SLOT HAVING LONG AND SHORT DIMENSIONS, SAID SHORT DIMENSION BEING GREATER THAN THE THICKNESS BUT SHORTER THAN THE WIDTH OF THE OUTERMOST ONE OF SAID ENLARGED REGIONS OF SAID SWITCH TERMINAL SUCH THAT, WHEN SAID CONSTRICTED REGIONS ARE POSITIONED WITHIN SAID SLOTS, SAID SWITCH MAY BE ROTATED TO LOCK SAID SWITCH TERMINALS TO SAID CIRCUIT TERMINAL. 